RAPID: A Community Test of Distributed Acoustic Sensing on the Ocean Observatories Initiative Regional Cabled Array

近年来，人们对太平洋西北部近海分布式声传感（DAS）的潜力产生了兴趣，在该地区进行试验将引起海洋学界的广泛兴趣。DAS在学术界是一种相对较新的观测技术，它利用重复的激光脉冲来探测光纤，并利用背散射光的相位变化来测量光纤的应变率。DAS可以工作到~100公里的距离，具有几米的空间分辨率和宽频率灵敏度。关于DAS信号对应变的反应，还有很多需要了解的。在陆地上，DAS已被广泛应用于地震监测和快速反应余震研究等领域。海洋中的DAS实验更具挑战性。直到2019年，海底DAS在学术研究中的潜力才得到证明。俄勒冈州边缘是世界上最具活力的海岸线之一，是测试DAS能力的绝佳地点，因此是研究风暴在海岸线附近产生地震噪声中的作用的理想场所，并有可能了解DAS是否以及如何用于测量沉积物交换。DAS也被认为是一种新技术，可能成为未来卡斯卡迪亚和其他地方近海地震和海啸预警系统的重要组成部分。计划关闭为在该地区测试DAS提供了一个很好的机会。一名加州理工学院的研究生将获得领导数据采集的经验，两名华盛顿大学的研究生将获得DAS/DTS数据采集的经验。这些pi正在利用2021年11月初海洋观测倡议（OOI）区域电缆阵列（RCA）的罕见计划关闭。随着RCA电缆与所有RCA岸上设备断开，分布式声学传感（DAS）和分布式温度传感（DTS）系统将连接到OOI光纤，并将进行测试，以确定潜艇DAS观察地震、海洋学、声学和大地测量过程的潜力。DAS对于在卡斯卡迪亚开发近海地震和海啸预警系统的工作具有潜在的重要意义，这一实验是在制定协议方面迈出的重要一步，这些协议可以支持将DAS用于东北太平洋的科学和减灾工作，同时满足国家安全要求。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In recent years, there has been interest in the potential of offshore distributed acoustic sensing (DAS) in the Pacific Northwest and a test in this region would be of widespread interest to the oceanographic community. DAS is a relatively new observational technique in academia that interrogates an optical fiber with repeated laser pulses and utilizes changes in the phase of backscattered light to measure the strain rate along the fiber. DAS can work to distances of up to ~100 km, has a spatial resolution of a few meters and a broad frequency sensitivity. There is still a lot to be learned about how the DAS signal responds to strain. On land, DAS has been demonstrated for a wide variety of applications including earthquake monitoring and rapid response aftershock studies etc. DAS experiments in the ocean are more challenging. It wasn’t until 2019 that the potential of seafloor DAS for academic research was demonstrated. The Oregon margin is one of the most energetic coastlines in the world and an excellent location to test the DAS capabilities and is thus, an ideal site to study the role of storms in generating seismic noise near coastlines and potentially understanding if and how DAS could be used for measuring sediment exchange. DAS has also been identified as a new technology that might form an important component of future offshore earthquake and tsunami early warning systems in Cascadia and elsewhere. The scheduled shutdown provides a great opportunity to test DAS in this region. A Caltech graduate student will get experience leading data acquisition and two UW graduate students will gain experience in DAS/DTS data acquisition. The PIs are taking advantage of a rare scheduled shutdown in early November 2021 of the Ocean Observatories Initiative (OOI) Regional Cabled Array (RCA). With the RCA cables disconnected from all RCA shoreside equipment, the distributed acoustic sensing (DAS) and distributed temperature sensing (DTS) systems will be connected to the OOI fibers and will undergo testing to determine the potential of submarine DAS to observe seismic, oceanographic, acoustic and geodetic processes. DAS is potentially of great importance for efforts to develop offshore earthquake and tsunami warning systems in Cascadia and this experiment represents an important step in developing protocols that can support the use of DAS for science and hazards mitigation in the Northeast Pacific while meeting national security requirements.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.